High molecular weight olefins, or “heavy olefins,” particularly olefins having carbon chains with 14 to 36 carbons, particularly 18 to 28 carbons, have found many utilities, especially in the production of surfactants for specialty applications. (As used herein, molecules with carbon chains having X carbons will be designated CX. Molecules with carbon chains have more than X carbons will be designate CX+.) The most significant growth in demand is expected in the area of enhanced oil-recovery processes, driven by an always continuing increase in crude prices. C18 to C28 olefins are especially desirable in the production of alkylbenzene surfactants and sulfonated surfactants used in tertiary oil-recovery processes.
Typically, heavy olefins are obtained from heavy feedstock, that is, feedstock having heavy olefins and high molecular weight paraffins (“heavy paraffins”). The heavy olefins are obtained by separating them from the heavy paraffins. However, it is very difficult and, thus, costly to extract the heavy olefins from the heavy paraffins. In addition, the heavy feedstock has a high fuel value in itself. In contrast, feedstocks comprising lower molecular weight (C5 and C6) paraffins are relatively inexpensive.
Accordingly, it is desirable to provide a method for making heavy olefins from feedstock comprising lower molecular weight (C5 and C6) paraffins. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.